"Which means that you can easily discover unprotected resources, but those that have already been found and shielded are off-limits." The Overlord completed the phrase for him.
"Exactly." Solus replied. "The Watchtower is a great tool since it works akin to my mana sense but has a much bigger range and usually not many people wear cloaking devices. At the same time, however, it's easily fooled.
"My guess is that the main purpose of the Watchtower is to find the magical resources that grow in the surroundings of a mana geyser without the need of scouting for hours.
"We can just conjure the tower, Warp to any geyser we discovered in the past, scan the area, and if there is nothing precious in the area we just have to rinse and repeat. With a bit of luck, we might claim an undiscovered magical mine.
"Even if the Council forces us to hand it over to a regional Lord, we can at least obtain a share of the goods."